'Single punch' universal flu vaccine comes closer to reality

Washington: A new study has revealed that a "single punch" universal flu vaccine may soon be a reality.

Researchers at McMaster University and the Icahn School of Medicine at Mount Sinai, New York say that a universal flu vaccine may be on the horizon, thanks to the recent discovery of a new class of antibodies that are capable of neutralizing a wide range of influenza A viruses.

Researcher Matthew Miller said that unlike seasonal vaccines, which must be given annually, this type of vaccine would only be given once, and would have the ability to protect against all strains of flu, even when the virus mutates as this would prevent the occurrence of flu pandemics and poor vaccine efficiency in the case of mismatches, which actually occurred this year.

In the study, researchers show that when comparing the potency of an isolated strain-specific flu antibody (the type that current vaccines generate) with an isolated broadly-neutralizing flu antibody (the type generated by universal vaccines) in a lab setting, the latter have much weaker neutralization activity than the strain-specific antibodies.

While this sounds worrisome, they also found that when they isolated these antibodies in their natural (polyclonal) setting from human blood, their potencies were comparable; with the broadly-neutralizing antibodies have the added benefit of being able to neutralize many strains of virus.

The research team also showed that the subtype of antibodies that are present in the lungs and upper respiratory system are particularly potent in neutralizing flu.

This is also very encouraging and provides guidance as to what vaccine would be best for delivering a universal flu vaccine, which is, inactivated versus live-attenuated, added Miller.

The inactivated vaccine or "flu shot" consists of virus particles that are grown in eggs under controlled conditions and are then killed using a detergent-based method.

The study is published today in the Journal of Virology.